Former Citigroup chairman Sandy Weill listed the 6,437-square foot apartment, which he paid $43 million for in 2007, back in November for $88 million which he promised would go to charity. A month later, Rybolovlev swooped in and bought the place for his 22-year-old daughter, Ekaterina.

According to Rybolovlev's team, Ekaterina will use the apartment when she visits New York. Many of the features customized for the Weill's, such as a rosewood library and oval bedroom, will remain in tact.